1.4 vs. 1.2

[DeadEyesSmiling]

I'm looking at getting a lens for future 35mm adapter use and was wondering if a 1.2 is really worth another $300 from a $140 1.4. Thanks for your feedback!

-DES

[William_Robinette]

I wouldn't.

[mvansomeren]

I've been reading up on specifically Nikon/Nikkor 50mm AI or AIS lenses for the same reason. Everything I've found says that, although the 1.2 and 1.4 lenses offer better low light performance, they also tend to have distortion at their fully open positions. I was initially going to buy the f1.4 lens, but now I'm going after the f1.8 because they don't have the distortion and, many articles that I've read, say that the f1.8 is produces a sharper image.

See for yourself:

http://www.kenrockwell.com/nikon/50-...ison/index.htm (http://www.kenrockwell.com/nikon/50-...ison/index.htm)

Also, you can google Nikon f1.4 vs f1.8 and find numerous other articles and discussions.

Now I think, from what I've read, it's a different story with Canon lenses but you'll have to investigate it further.

[frobozz]

Yeah, gotta be more specific about what brand you are talking about. It depends on which lenses you are looking at.

In the Canon FD range, the 1.8 is the throwaway lens that came free with cameras, the 1.4 is one of the nicest lenses on the planet, and the 1.2 is... not generally regarded as being as good as the 1.4, despite the higher price! Unless you get the much-rarer 55/1.2 Aspherical version, but even that is basically only as good as the 1.4, for a ton more money (and one stop.)

As far as lenses being soft when shot wide open: that's true of all lenses. So you might need to stop a 1.2 or 1.4 lens down to reach its peak performance... but you also have to do that with a 1.8. You're still gaining one or two stops net.

Duncan

[Tomas Riuka]

i'd say always get the fastest you can, you can always stop down, but neve open when you don't have where, especially with 35mm adapter

[mvansomeren]

As far as lenses being soft when shot wide open: that's true of all lenses. So you might need to stop a 1.2 or 1.4 lens down to reach its peak performance... but you also have to do that with a 1.8. You're still gaining one or two stops net.

Duncan

I was referring more to actual distortion, than softness when wide open. According to the article in the link I provided, there is picture distortion on faster lenses that is not present on the 1.8. Same issues with CA as well. But, again, I've only read that information and haven't seen it myself since I haven't yet purchased a lens. However, more than one article has mentioned that problem.

[THX-1138]

It's worth it if all your other lenses are the faster stop.

That will make your iris consistant throughout your lens package.

Contrast and color rendition should match better.

[jenningsp]

it really depends on what adapter you want to use it on....

fstops on lenses don't work the same way on adapters as they do on film and dslrs.

it's all to do with the GG and how diffuse it is. the more diffusion, the more of a difference in the brightness you will see when you adjust the aperture.

on the sgpro, an f1.4 lens is only 1/10th of a stop faster than an f2 lens... not a stop faster as you would believe. you would see even less of a difference on a less diffuse adapter like the LEX or the Brevis. likewise you would see more of a difference on the G35 and the old M2. i believe the current M2 would be about the same as the sgpro.

i don't have an f1.2 lens but i'd bet it's only about 1/20th of a stop faster than the f1.4. 1/10th of a stop is nothing. you can't even see the difference unless you flick back and forth. and even then it's only slight. so i can't imagine what 1/20 of a stop would be like...

there is a "roll off" though. past f2, you begin to see more of a difference. i think the difference between f2.0 and f2.8 is bout 1/2 a stop. and the difference between f2.8 and f4 is about 3/4 of a stop. it's not linear. the roll off is different for all the adapters and is determined by the diffusion again.

here are some example pictures.


http://e.imagehost.org/0796/dvxf2_8_sgprof1_4.jpg

http://e.imagehost.org/0110/dvxf2_8_sgprof2.jpg



and this is what a stop difference is supposed to look like...

http://e.imagehost.org/0518/dvxf4_sgprof1_4.jpg



is the f1.4 worth the money over the f2? or the f1.8?

[TimurCivan]

I have the canon 55mm F1.2 SSC lens... worth every penny.

so gorgeous.

[DeadEyesSmiling]

Thanks so much for all the feedback so far! I am looking at going Nikon because I already own a DSLR and would like to stick with compatable lenses, but you've given me tons to think about.

-DES

[frobozz]

I have the canon 55mm F1.2 SSC lens... worth every penny.

so gorgeous.

That's a good point even outside any differences in light transmission: the sharpness and insanely narrow depth of field on those big-aperture lenses just can't be replicated by the less esoteric lenses.

A still camera example of the FD 55/1.2 Aspherical:

http://www.backglass.org/duncan/bandw/parker_55_20080126_01.jpg

Duncan